AML exosomes enhanced TGFβ1 signaling via TGFβRI/II on the surface of primary aNK or NK-92 cells as evidenced by increased phosphorylation of SMAD 2/3 and its down-regulation by LY2109761, an inhibitor of TGFβ receptor signaling. This evidence concerns the gene TGFB1 and acute myeloid leukemia.